Bonus from the Concealment Expert skill is now applied to the basic visibility of the ship similar to the camouflage modifiers and the Masking System mod.1 modernization. Previously, this bonus affected the fines to visibility, such as fire, main battery, AA defense and anti-torpedo armament.

EU Community Contributor Carnotzet dug out an answer from the RU Forums regarding this issue as well:

Sub_Octavian “explained” the reasoning behind the change in this post.

“This decision was made to make the mechanics more understandable and logical. The penalty when firing is added to the detection range without any modifiers affecting it. On the other hand, all modifiers are added multiplicatively to the detection range (firing penalty is then added to the total). This way, there’s no subtlety in that cammos and upgrades work differently than skills.”

In brief, they want all modifiers to work the same way and they decided to do it the “nerf” way. What bothers me (and I guess many people) is that it wasn’t documented in the patch notes. Well actually it was, in the Russian patch notes, but I guess we’re not worthy enough to have the same patch notes.

So stealth firing is still possible, but any skills, modules or camos do not affect the penalty for firing any more. For example:

Example: Assume you have a ship with a normal visibility of 10 km and a maximum range of 15 km. You visibility does increase by 5 km when firing. We now apply a 10% bonus to visibility.